In bulk polymerization techniques for the preparation of aminoalkylpolysiloxanes, it is not uncommon to employ an aminoalkyl siloxane polymer or an aminoalkyl trialkoxysilane as a precursor. However, aminoalkyl siloxane polymers are generally quite viscous and very sticky materials, and these properties make it difficult to pump the aminoalkyl siloxane polymer through existing equipment, and make it difficult to disperse the aminoalkyl siloxane polymer in the reaction medium. While aminoalkyl trialkoxysilanes generally disperse well in the reaction medium, they liberate significant amounts of an alcohol as a by-product.
In contract, and according to the present invention, the dialkyl, alkyl aminoalkyl cocyclic siloxane is (i) low in viscosity, (ii) nonsticky, (iii) easy to pump through existing equipment, and (iv) it can easily dispersed into the reaction medium. In addition, the dialkyl, alkyl aminoalkyl cocyclic siloxane liberates no by-products.
In emulsion and microemulsion polymerization techniques for the preparation of aminoalkylpolysiloxanes, it is also not uncommon to employ an aminoalkyl trialkoxysilane as one of the precursors in order to impart functionality to the siloxane polymer. However, aminoalkyl trialkoxysilanes typically have a considerable solubility in water, and therefore only partially incorporate into the siloxane polymer droplets formed during the ring opening polymerization reaction. As a consequence, one can only expect a low level of the aminoalkyl trialkoxysilane to become incorporated into the siloxane polymer. In addition, as noted above, the aminoalkyl trialkoxysilane generates a significant amount of alcohol as a by-product, most commonly methanol, according to the reaction: EQU RSi(OCH.sub.3).sub.3 +3H.sub.2 O.fwdarw.RSi(OH).sub.3 +3CH.sub.3 OH.
While methanol is not classified as carcinogenic, it can be acutely toxic if ingested, and may even be fatal or result in blindness. Methanol is a general irritant to the skin and mucous membranes, and prolonged skin contact with methanol vapor or liquid can cause dermatitis. Therefore, it would be advantageous in applications especially in the personal care arena, to eliminate its presence.
In contrast, and according to the present invention, one can expect that the extent of incorporation of amine functionality into the siloxane polymer will improve with the use of the dialkyl, alkyl aminoalkyl cocyclic siloxane due to its increased nonpolarity and hence its decreased water solubility. In addition, the dialkyl, alkyl aminoalkyl cocyclic siloxane liberates no by-product of any kind.